Xerox Corporation

Lawrence J Mason

Richard F Lehman

Thomas J Hammond

David K Shogren

Jacob N Kluger

William L Statt

James G Stoffel

Richard G Ermer

Randolph A Bullock

Roland W Porth

Lamp operating voltage levels are reduced by using a boost circuit to initiate a triggering sequence in one of two lamps connected in series. The boost circuit is connected across one of the lamps at a connector point common to the two lamps. In a preferred embodiment, trigger pulses are applied sequentially to each lamp, the boost circuit voltage contained in an associated capacitor is discharged through the first triggered lamp, causing it to begin conduction. Most of the voltage from a main storage capacitor then becomes available to break down the second lamp.

Triggering circuit for series connected flash lamps

In a full-frame flash electrophotographic printing machine, an imaging system is provided which incorporates a flash lamp directly coupled to an ac line input to enable document exposure. The imaging system also includes a lens whose movement is synchronized with a moving photoreceptor so that an exposure occurs registered at the same image area of the photoreceptor. The invention further includes circuit means for detecting zero crossing points of the line voltage and for generating signals which are used to trigger the lamp into operation at some point during an 8 msec, half cycle of line operation. Further circuit means are provided for controlling exposure levels to conform to detected density of the document being copied. In a second embodiment, the control circuitry is used to couple the ac line into a flash fuser assembly to fuse a transferred image on an output record medium.

Electrophotographic reproduction machine with document exposure system

An optical scanning and illumination arrangement is provided for a document reproduction machine which includes a plurality of linear motors to drive the moving scan/illumination carriages. Each linear motor is under the control of a digital control circuit which, in turn, is under the control of a supervising circuit which maintains the status of machine operation and generates appropriate signals to control the individual digital control circuits.

Optical scanning system utilizing linear drive motors

A selective color copyability illuminator includes a pair of lamps having complementary spectral emission. The ratio of the lamp outputs are adjustable to enhance a first color of an original to be copied while suppressing the second color. The power input to the lamps is also continually adjustable to maintain a desired exposure level at an imaging plane. In a preferred embodiment, a dichroic reflector is utilized with each lamp to enhance system efficiency.

Document reproduction device utilizing a selective color illuminator

A circuit is provided for regulating the application of power to a load which is relatively insensitive to rapid power fluctuation of the type exemplified by typical AC line sources. In one embodiment, an AC line source is applied at a controlled rate to a tungsten lamp whose operation is controlled by a transistor switching network. The transistor operation, in turn, is controlled by comparing a portion of the rectified signal with a signal proportional to the light output of the lamp.

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Penfield, NY, United States of America

Lawrence J Mason